Coimbatore's name is derived from Koyanputhur, named after chieftain Kovan who ruled the region. Over time, Koyanputhur evolved to become Coimbatore. The city has two special economic zones, Saravanampatti and Peelamedu, known as TIDEL PARK and CHIL-Cbe Hi-Tech Infrastructure. The largest trade fair complex in the country was built in six months and is owned by CODDISSIA, also having the country's largest pillar-free hall. Coimbatore has sister city relationships with Toledo, US and Esslingen, Germany.