About 4 km long and 2 km wide, Ko Lan is the largest of the "near islands" off south Pattaya, at the southeast end of the Bay of Bangkok, and on the east side of the Gulf of Siam.
It is an island of hills covered with low tropical forest. A Buddhist shrine is located at its highest point, 180 m above sea level. The island has two small villages, Baan Ko Lan and Baan Krok Makhan, where there are lodgings and restaurants. Ferries connect Koh Larn to the mainland.
Most of Ko Lan's beaches are on its west side. Most visited is Tawaen Beach, where there is a small harbor. The beach is lined with small tourist shops and restaurants. Other beaches are Tonglang Beach, Tien Beach, Samae Beach, and Naon Beach.
Ko Lan is inhabited by about 3,000 residents in 1,000 households, mostly clustered around the ferry pier.