Sinnakarachchi is the name of the lagoon of Nilaveli. It's situated to the north of Trincomalee. The famous holiday destination Nilaveli Beach is a 7.5 km long and 1.5 km wide spit of land in between the ocean and this Sinnakarachchi Lagoon, which opens to the sea north of Nilaveli, just below the bridge connecting the villages of Irakkakandi and Kumpurupiddi. Actually, the former village is also namegiving to the lagoon of Nilaveli, as Sinnakarachchi Lagoon is sometimes called Irakkakandi Lagoon. The mouth of the lagoon near Irakkakandi village is not far away from the maritime National Park of Pigeon Island. Boat tours to all maritime places of interest near Nilaveli - Pigeon Island, Coral Garden plus Red Rock, and Sinnakarachchi Lagoon - are offered by the Nilaveli Tourist Boat Services Cooperative Society Limited, which is a registered body of boat owners in and around Nilaveli. They also organize dolphin and whale watching tours and deep sea fishing. Their office is at the beach site of Nilaveli.

Sinnakarachchi Lagoon has two separate major arms, covering 780 hectares altogether. The main part behind Nilaveli Beaches stretches 9.5 km to the south in a slightly curved way. An even more curved northern arm stretches 5 km inland. The calm lagoon, which is connected with the ocean only by a small natural canal, is used as a sheltered anchorage for fishing boats.

With a maximum depth of 2 m, Sinnakaracchi Lagoon is fairly shallow and its water is more than brackish, actually it is categorized hypersaline. At several places along the lagoon's shores, crystallization of salt can occur during the dry season naturally. However, due to ist high salinity, salt pans for salt production were developed additionally, similar to those in Puttalam Lagoon at the west coast. Nilaveli Beach holiday makers interested in seeing salines, however, should travel 2 km further north to Periyakarachchi Lagoon near Vallipunam, where more salt pans can be seen, very close to the main road to Pulmoddai (B 424).

Due to ist mangrove swamps, seagrass beds and inter-tidal mudflats, Sinnakarachchi Lagoon is an important natural habitat of Sri Lanka's Eastern Province, particularly for waterbirds. However, the eco-system is threatend by the development of new aquaculture, whereas small subsistence fishery is the traditional way of using the lagoon. Wild elephants are known to frequent the area to the west of Sinnakarachchi Lagoon.

Boat services to the wetlands of Sinnakarachchi Lagoon start near Pulmoddai road (B 424) of Nilaveli Beach.

The Magul Maha Vihara, also spelt Maghul Maha Viharaya, is an ancient monastic complex situtated close to the small Lahugala-Kitulana National Park in the hinterland of Arugam Bay. Among the remnants of the Anuradhapura period, Magul Maha Vihara is one of the most fascinating archaeological sites in the southeast of Sri Lanka. ‘Magul’ means ‘wedding’ in Sinhala. The platform in the southwestern corner of the rectangular monastic complex is believed to be the location where the wedding of King Kavan Tissa from the southern kingdom of Rohana and Princess Viharamahadevi from Kelaniya near Colombo took place in the 2nd century BC. She will become the mother of Dutthagamani alias Dutugemunu, the most famous king of Sinhalese history. According to legend told in the Mahavamsa, Viharamaha Devi volunteered to sacrifice herself to the sea in order to appease the gods who punished her father’s kingdom by sending a tsunami. But the princess was safely carried in a golden vessel over the ocean, landing at a place near the Muhudu Maha Viharaya in Pottuvil (others say in Kirinda in the Southern Province), where the encounter between the local king and the beautiful princess took place. The marriage is said to have been celebrated in Lahugala on the platform now called Magul Maduwa or Magul Poruwa. It‘s namegiving to the entire ancient complex.

Actually, the buildings are not from the pre-Christian centuries but about one millennium younger, roughly from the late Anuradhapura period. An important stone inscription at the archaeological site dates to an even later period (14th century). The layout of the monastic complex is regular and follows a pattern called „Pabbata Vihara“, which became quite common in the Culturl triangle during the 7th and 8th century, but Magul Maha Vihara is one of the few examples of this systematically arranged monastic compounds in southern Sri Lanka.

A rectangular paraket wall in north-south direction surrounds the entire complex, which covers an extent of around 10,000 acres. The four major buildings of a monastery are arranged symmetrically in the four corners of the premises. Besides the chapter hall, which serves for the higher ceremonies of the monks, these edifices are dedicated to objects also venerated by lay persons (pilgrims and other guests of the monastery). These objects of veneration are a stupa, a Buddha statue inside a hall called image house (Pathimagara), and a platform for tree worship (Bodhigara). Most likely, the platform now called wedding terrace was the Bodhigara of the ancient monastery now called Magul Maha Vihara.

The moonstone (Sandakada Pahana) of the Magul Maha Vihara in Lahugala is of special interest for lovers of ancient Sinhala-Buddhist art. It’s the largest ancient moonstone with intricate carvings in the southern half of the the island. In fact, there are only very few carved moonstones in southern Sri Lanka. Hence, the moonstone of the Magul Maha Vihara is the best instance of this typical and classical sujet of Sri Lankan art, which is without equally elaborate paragons in India. There is one feature that can be seen nowhere else than in the Magul Maha Vihara. Elephant carvings are very common on classical Sri Lankan moonstones. But only in the Magul Maha Vihara the elephants are depicted with riders. Mahouts can usually not be seen on stone carvings from the Anuradhapura period and not on any other moonstone in the entire world.

The above text in italic letters is cited from the signboard of Sri Lanka's Archaeological Department,
which is placed near the moonstone of the Madul Maha Vihara in Lahugala.