sting places and crossing points are significant clues. Construction of permanent stone bridges across the rivers is an archaeological evidence of a well established road system. In accordance with the geographical location wooden bridges were constructed on rock lying under the river. Still remaining infrastructural features are the stone and wooden bridges ambalam or resting houses, gavukanu or distant marking, wells, temples and small tanks. By the Grand trunk road running from Pataluputra to Peshawar (Purushupura) pillars were installed after every 2.5 miles for the convenience of travellers (K A. vol2:.53;Needham, 1971:.5-6;Rahman Dar 2000:159-160,179) Those pillars were identical with present day mile posts (kos miner).
From the remains found in some main roads in Sri Lanka it is understood that the same technique had been practised in country too. Isolated stone pillars found to the north of Abhyagiriya on the ancient western high way to Mahatittha road and the stone pillar discovered by Bell as a gavu pillar close to Vijayarama temple complex (north of Anuradhapura city) are some of the remaining evidence to say that the technique followed in India has been followed in Sri Lanka too (Bell,1892:3-4). This is further understood from the gavu pillars discovered from the main road within the city limits of Anuradhapura and those found by the southern high way supposed to have been fixed during Polonnaruva period (Vidanapathirana, 2016). According the practise of setting gavu pillars had been a continuing practise in Sri Lanka. Apart from the about archaeological evidences regarding the fixing of gavu pillars one could fine as from the Hatadage wahalkada inscription of king Nissankamalla that says Tam hinduva akuru kotava Nissanka gavu yay nam kota (Wickremesinghe.1927:119)These is a whale street of gavu pillars discovered though exploration the Rohana high way and the main road way to the east. A few gavu pillars on the way of Magana minor port are being carried close to Mahavilachchiyavava Magana port is situated to the south of Mahatittha in the western coast (Vidanapathirana 2012,2013,2016).
There is evidence of a rectangular foundation among the ruins adjoining Abhyagiri watch found in this area is inscribed mahavata chathussala meaning a building open from all sides to same as an open hall or an ambalama.(Bell,1891:5,1893:4; Paranavitana,2001:150-151)
Bell has reported that the foundation on a rocky plane at Palugasvava village close to southern high way to be another ambalama. In metropolitan area ambalamas were constructed at points where cross road meet. Bell has recorded about two ambalamas constructed at a junction where three road meet (tun-man-handiya) on the southern and western high way. There had been another ambalama at a junction where four road meet (satara-man handiya) resting place for travelling from the northern eastern and north-eastern area.There is evidence of an ambalama and a gavu pillar in the city limits close to Tissavava on the southern high way. Hattavanagalla vihavamsaya andJataka-atuva-gatapadaya supposed to have been written at the time of Parakkramabahu II (1236-1270) and they mention about an ambalama and a wooden bridge constructed near Tissavava. Jataka-atuva-gatapadaya names the bridge as puvaraheya (Ja.16;Hat.21-25). The bridge is supposed to have been constructed on stone pillars set across a stream and they are paved with wooden planks. Road leading to Dakkhina- desa and Uruvala port had to cross this wooden bridge.During the reign of Parakkramabahu II there is recorded information to say that the construction of ambalam and bridges were done with the royal patronage. Stone bridges belong to historical age can treated across river and streams in the Dry Zone have been
Thus on the northern high way bridges at Halpan ela, Malvatu Oya, Kandara Uya near Tulavaliya, Kal Aru across Pavakkulam and Ulukkulam constructed to the advancement of infrastructure of northern high way (Vidanapathirana,2016). On the eastern high way up to Gokannatittha Malvatu Oya stone bridge at tai eastern