Sri Lanka
2nd cent BC - present

For each section there exists a Google-Earth.kmz file which locates the places on the globe. These files open only in GE, which you must have on your hard-disc.
Sinhale - Sri Lanka

Sri Lanka
History of Buddhism
2nd cent BC - present

Avukana Buddha Statue, 5th cent AD
Photo and text Wikipedia

Buddhism in Sri Lanka is primarily of the Theravada school, and constitutes the religious faith of about 70% of the population. According to traditional Sri Lankan chronicles (such as the Dipavamsa), Buddhism was introduced into Sri Lanka in the 2nd century BC by Venerable Mahinda, the son of the Emperor Ashoka. The Pali Canon, having previously been preserved as an oral tradition, was first committed to writing in Sri Lanka around 30 BC.
The Chola brought the Mahayana to Sri Lanka (5th-11th cent AD) and suppressed the Theravada monasteries. TheTheravda lineage was only revived in the 13th-15th cent through contact with Myanmar and Thailand. Official neglect under colonial rule, created great challenges for Theravada Buddhist institutions in Sri Lanka. During the 19th cent revivals and resurgences have kept the Theravada tradition alive
Only three of the many sites are included here.
Reference H.R. Perera, accesstoinsight.org

Anuradhapura Sri Lanka
3rd cent AD

This is a UNESCO Heritage site. The citation says:
“This sacred city was established around a cutting from the 'tree of enlightenment, the Buddha's fig tree, brought there in the 3rd century B.C. by Sanghamitta, the founder of an order of Buddhist nuns. Anuradhapura, a Ceylonese (sic!) political and religious capital that flourished for 1,300 years, was abandoned after an invasion in 993 is now accessible once again.” Text UNESCO

Anuradhapura, Thuparama Stupa, 3rd cent AD

Photo Panoramio

Thuparama Stupa in which was enshrined the collarbone of the Buddha is considered to be the first dagoba built in Sri Lanka following the introduction of Buddhism. The dagaba was destroyed from time to time. During the reign of King Agbo II it was completely destroyed and restored. What we have today is a reconstruction of the dagaba.
The columns sourrounding it are remnants of a "vatadage", a cupola (19th cent?)) that originally surrounded the stupa as shown in the model below. Such a structure could only have been built in the 13th-14th cent by Isalmic architects. Domes of this kind are unknown in India before the 19th cent..

Model of the “roof” structure, "vatadage”, Photo and text Wikipedia

Anuradhapura, Jetavanaramaya Stupa
3rd cent AD

Jetavanaramaya Stupa in Anuradhapura, Sri Lanka.
Photo Panoramio

King Mahasena (273-301 AD) initiated the construction of the stupa. The largest brick stupa which rivals the Great Pyramids of Giza in size. The stupa has recently been freed of overgrowth - but not white-washed yet - so that the brick structure is visible.

Nalanda Gedige
3rd cent - 11th cent AD

Nalanda Gedige in Sri Lanka appears to be a Theravada, Mahayana and Tantric sanctuary of the 3rd cent - 10th century AD in Sri Lanka. It was brought to my attention by Janaka Bandara. New photos by Radek Scibior (private communication 2008) allow a better guess at the date and origin of the structures
Very little is known about this site. An inspection of the GE map shows two structures: a circular stupa and a rectangular temple.

The circular building turns out to be an early Buddhist brick stupa
of the 2nd or 3rd cent AD,

The rectangular structure is a temple, named after Nalanda ,India, (9th cent). It is made of local lime stone and appears to date from the 9th or 10th cent (also related to Chola temples). It's external sculpture, heavily weathered, is decidely Tantric. It may well be late Mahayana Buddhist but might also be Shaivite Tantric temple.

A Buddha

and a Tantric sculpture
on the outside of the temple, 10-11th century

The intriguing question is that this site lies in Shri Lanka which originally (2nd cent BC - 5th cent AD) was Theravada Buddhist. Sri Lanka was partially converted to the Mahayana by the Chola in the 5th cent AD and in the 13th cent it was reconverted to the Theravada by missionaries from Southeast Asia. - If Buddhist this would be one of the rare Tantric sites known on the subcontinent and their most southern one.
My thanks go to Radek Scibior, who contributed the photos. I would appreciate any comments from knowledgable archeologists.