The ancient city of Anuradhapura was first settled ca. 900 B.C., and served off and on as the capital of the Sinhalese Kingdom until ca. 1100 A.D., when the capital moved further south. The city was quite large in its heyday, and so there is a lot of archaeology to see.
A $25 USD ticket will get you day admission to all the sites of Anuradhapura itself, and admission is included in the Cultural Triangle ticket$50 USD. Tickets can be purchased at the Archaeology Museum. Alternatively, most tuk-tuk drivers can get you in without paying the ticket. Some of them offer to take you in and tour you around for a price lesser than the price of the ticket. Decide for yourself between supporting local economy or supporting maintenance of historical monuments.
Bodhi Tree Temple
The Sri Maha Bodhiya, is the second most sacred place in Sri Lanka, after the Sri Dalada Maligawa, or Temple of the Tooth, in Kandy. The Bodhi Tree is allegedly a cutting from the original Bodhi tree under which the Buddha gained enlightenment, and has been continuously guarded for over 2000 years, making it the oldest historically authenticated tree in the world. The temple complex is surrounded by walls, and is quite busy with monks and worshipers. Due to terrorist activities in the 1980s, it is not possible to drive up to the temple, and one must go through a metal detector before entering the complex. Bags will be checked, and it is advisable to leave luggage at the hotel, as it will not be allowed near the site. Shoes can be left near the entrance. It is polite to leave a tip.Ruwanwelisaya
the oldest and most voluminous stupa at Anuradhapura, has been fully restored, painted white, and is currently a centre of worship. Walk from the Sri Maha Bodhiya, past the Brazen Palace an ancient palace that once supported a bronze roof to the stupa. There are several image houses at the stupa, as well as four smaller stupas in the four corners of the complex. Please be respectful of the worshipers at the site.The Archaeolgy Museum
Showcases many of the artifacts found at the site, from jewelery and gems to coinage and pottery. The museum is more focused on religious and elite objects, although some commoner artifacts are also shown.The Folk Museum
Showcases the archaeology of Anuradhapura from a more folk perspective.Jetavana
Large stupa Buddhist worship structure. Also known as "Dagoba", currently undergoing restoration work. At ~120m 400ft. tall, this was the third tallest structure in the ancient world after the Great Pyramids at Giza, and the largest in Sri Lanka.The Citadel
This was the secular centre of the city. The Gedige and other palaces can be found here, as well as the old city walls.The Moonstone
Moonstones, to be found throughout Anuradhapura, were at the entrances to monasteries, and represented the movement from the secular to the sacred worlds, by following the path to enlightenment, as carved into the moonstone. This moonstone is of particular note, for its size and impressive decoration.The Western Monasteries
These monasteries represent a different take on worshiping the Buddha than can be found in the main part of the ancient city. Whereas many monasteries were opulent and richly adorned, the Western Monasteries sought a more orthodox existence, without any sort of decoration within the monastery, save for urinal stones. Urinal stones were often very richly adorned, and the symbolism here need not be explicitly stated.Lovamahapaya
The 1600 stone pillars that we see today are what are left of an enormous building. Also called the Brazen Palace, this nine-storey monastery was once home to a thousand monks, whose duties included tending the sacred Bo tree, which grew right next to the building. King Dutugemunu the palace founder saw to it that the roof of Lovamahapaya was covered in bronze tiles, and that its walls were decorated with silver and precious stones.