Merv is an old city on the Silk Road 35 km east of the modern city of Mary in the Mary Province of Turkmenistan. There is a state park for the old city center, a UNESCO World Heritage Site.

The oasis of Merv is in the Karakum Desert at the crossing of the Amu Darya (or Oxus) River and the main route to Bukhara and Samarkand. It occupies an area of 86 x 75 km. Today the main city is Mary, which was mostly built during the Soviet period. However there are ruins of at least five older cities.

The earliest Bronze Age centers in the oasis of Merv date from 2500 BC to 1200 BC. They are in the northern part of the oasis.

The historic urban center developed around 500 BC in the eastern part of the oasis. It consisted of several walled cities, occupying an area of more than 1200 hectares. The oldest of these cities is Erk Kala. According to the famous trilingual inscription of Darius the Great at Behistun (Iran) Erk Kala dates back to the Achaemenid period (519 to 331 BC). The oasis was part of Alexander the Great's empire. Pliny the Elder reported that the city was founded by Alexander himself. It was rebuilt by the Seleucid king Antiochus I Soter (281 to 261 BC) and named Margiana Antiochia. This city is identified with Erk Kala and Giaur Kala and was occupied in the Parthian, Sasanian and early Islamic periods. It is suggested that Greek and Roman soldiers who survived the defeat of the Romans against the Parthians at Carrhae in 53 BC settled at Margiana. Islam was dominant after the death of the last Sasanian King Yazdigird III (651 AD).

The medieval city from the Seljuk period was erected west of the Giaur Kala. It was walled by Sultans Malikshah and Sanjar in the 11th and 12th century. The city extended over more than 600 ha. It was the capital of the Seljuk Empire (11th to 13th century) and one of the most important cities in this period, and by some accounts the largest city on Earth. It attracted scholars from all over the Islamic world, such as the famous astronomer and poet Omar Khayyam and the geographer Yaqut al Hamavi.

The city was sacked by the Mongols in 1221 and never fully recovered. Later (1370-1405) it became part of the empire of Tamerlane. The new city Abdullah Khan Kala was erected by Shah Rukh (1408-1471) on a new site to the south of Giaur Kala. That was destroyed by the Emir of Bukhara in the 18th century.

Map of Merv

A drive from Mary to Merv and back, including visiting several sites of own choice (total 4 hours) cost 150 manat after negotiating (updated August 2018).

• Mary Museum, Mary. Tu-Su 10:00-17:00. Exhibits from excavations of Bronze Age Gonur, Merv and Altyn Depe, ethnographic collection on the life of the Turkmen people (carpets, traditional clothes, wedding dress, silver jewellery, complete yurt) US$1, camera US$5. 
• The Bronze Age Settlements Kelleli, Adji Kul, Tai, Gonur Depe and Togoluk date from 2500 to 1200 BC. They are situated in the Northern part of the oasis. Kelleli 3 and Kelleli 4 have a double external wall with towers and houses. Both sites are poorly preserved, but delivered important information of Margiana in the Middle Bronze Age. Taip illustrates the transition from Middle to Late Bronze Age. Gonur Depe is the largest Bronze Age site in Merv oasis. It covers an area of 55 ha. Excavations have revealed a huge palace, a fire temple and a large necropolis from the Late Bronze Age. Remains of large fortified buildings have been discovered in the excavations at Togoluk.
• The Iron Age Settlements, 37.75136361.9980341 Yaz Depe and 38.06611162.08612 Takhirbaj Depe, in the northern part of the oasis date from 1200 to 300 BC. Takhirbaj Depe was the most important Iron Age center in this area and was occupied throughout the Achaemenid period. During excavations at Yazd Depe a great number of ceramics was found, providing the basic typology of this period. The well preserved fortress of Gobekli from Parthian-Sasanian times is nearby.

The historic urban center consist of three areas: Erk Kala, Giaur Kala and Sultan Kala.

• 37.66958862.1925413 Erk Kala. Dates from the 6th century and covers an area of about 20 ha. It consists of a wall and moat. The surviving walls are up to 30 m high. (updated Feb 2016)
• 37.66076162.1894194 Giaur Kala. Dates from around 1000 AD. It is roughly square in plan and its walls are about 2 km long. The Ben Makhan Mosque in the center is hardly recognizable. The Buddhist stupa and monastery in the south east corner of Giaur Kala are considered as the westernmost excavated example. (updated Feb 2016)
• 37.66506362.1642825 Sultan Kala. Dates from the 11th century. Sultan Kala means 'fortress of the sultans'. It is west of Giaur Kala. Merv became the capital of the Seljuk State in the 11th and 12th centuries. In this period the city reached its greatest prosperity. The city was surrounded by a fortication and a moat by order of sultan Melik Shah. The walls of the medieval city and the citadel Shahriyar Ark are 12 km long. (updated Feb 2016)
• 37.66608262.1459036 Mausoleum of Mohammed ibn Zayid. The nearby Mausoleum of Mohammed ibn Zayid was built in the 12th century in honour of Mohammed ibn Zayid, a major representative of the Shi'iet branch of Islam and descendant of caliph Ali in the fifth generation. Mohammed ibn Zayid was the head of a revolt against the Omayads in the 8th century. The revolt was suppressed within a year and Mohammed ibn Zayid was killed. The fine Kufi inscription in the chamber and the original decorated brick facade of the prayer hall are especially remarkable. The mausoleum is considered one of the best examples of Islamic architecture. (updated Feb 2016)
• Greater and Lesser Kyz Kala. (updated Feb 2016)
• 37.66749662.17757 Abdullah Khan Kala. Abdullah Khan Kala is the fortress erected by Timur's son Shahrukh in the 15th century. The fortress was lined with mud bricks from the outside and had 44 watch towers. The fortifications were surrounded by huge moats up to 30 m wide, filled with water. In the citadel, only few walls of the palace have survived. The walls, however, are of outstanding interest, as they show the evolution of military architecture from the 5th century BC to the 15th/16th century AD. (updated Feb 2016)
• The fortresses of Gobleki, Uly Kishman and Garry Kishman formed part of the earthen ramparts, 30 km long, built for protection against invasions from the steppes in the North.
• Geok Tumbaz Mausoluem. (updated Feb 2016)
• Seljuk Talkhattan Baba Mosque. The magnificent mosque dates from the 12th century. (updated Feb 2016)
• The Mausoleums of Imam Bakr and Imam Shafi. In the Talkhattan cemetery. (updated Feb 2016)
• Bairamalikhan Kala. The fortress dates from the 18th century. It is a three walled structure adjacent to the western wall of Abdullakhan Kala. The length of the western wall was 750 meters, the northern and southern walls were 500 m long. Only fragments of the southern and northern walls have survived. (updated Feb 2016)
• 37.66427362.163678 Mausoleum of Sultan Sanjar. The Mausoleum was built in the center of the Seljuk city. It is also called 'Dar-al-Akhyre (The Other World). Ajmad Sanjar (1085-1157) was sultan of the Great Seljuq Empire. He was one of the last great Seljuk and was described as brave, generous and chivalrous, a perfect Iranized Turk, defender of the Persian civilization and one of its legendary heroes. At the time of the division of the reign among the sons of Malkikshah he became governor of Khurasan at the age of ten or twelve. His principal residence was Merv. He installed vassal rulers in Transoxania and Afghanistan and became lord of an extensive sultanate in the Iranian East. In 1141, however, Transoxania was conquered by the Kara-Khitai, who had migrated from China to the Issyk Kul. In 1153 tribes of Oghuz rebelled against Sanjar, took him prisoner and plundered Merv. Sanjar freed himself 3 years later and died in 1157. Finally, Sanjar had failed to create a lasting Seljuk state in the Iranian east. During the siege of Merv by the Mongols in 1221 the body of the sultan was reburied in an unknown place. The mausoleum was constructed by order of Sultan Muizeddin Sanjar. Due to the fine brickwork, the carved stucco and the surviving mural paintings it is one of the most outstanding buildings of the Seljuk period. 

Owing to its historical significance (and its UNESCO status), pretty much everything to do in Merv relates to visiting the ruins. Wander the ruins and get a feel for what this city must have been like during its heyday.

There are restaurants and hotels in Mary.

Aside from Mary, visitors to Merv will go on in one of two directions:

• The first is to go to Ashgabat, the capital of Turkmenistan
• The second is to go to Turkmenabat up near the border with Uzbekistan

The ruins of Gonur Depe are close enough that some tours will hit each site on adjacent days.

For those who are fans of Great Game history, the Panjdeh area is south of Merv and has some monuments. This is where the Russians made a final push to annex territory before the borders of Afghanistan were defined in the 1800s.