Discoveries of Roman gold coins in various sites attest to extensive South Indian links with the outside world. As with Pataliputra in the northeast and Taxila in the northwest (in modern Pakistan), the city of Madurai, the capital of the Pandyan Kingdom (in modern Tamil Nadu), was the center of intellectual and literary activity. Poets and bards assembled there under royal patronage at successive concourses to composed anthologies of poems and expositions on Tamil grammar. By the end of the 1st century BCE, South Asia was crisscrossed by overland trade routes, which facilitated the movements of Buddhist and Jain missionaries and other travelers and opened the area to a synthesis of many cultures.