I spotted this Monitor lizard in Khao Sam Roi Yot National Park, Thailand, whilst on my way to Tham Phraya Nakhon Cave. I got a few photos to add to My Thailand photo collection, but once I got too close, it retreated back under the concrete slab, which you see in the photo below.

Monitor lizards are quite widespread throughout Thailand and South East Asia. In Thailand, all Monitor lizards are protected; places you might see Monitor lizards in Thailand include National Parks such as Khao Yai. Lumphini Public Park in Bangkok has a few resident Monitor lizards which have become accustomed to Humans, and they can be easily viewed.
Don’t be surprised if you see a monitor lizard crossing the road. They are commonly seen in built-up areas; even the sprawling metropolis of Pattaya has resident monitor lizards. Monitor lizards are often spotted in the area around Na Jomtien Beach in Pattaya.

Monitor lizards can grow up to 9 feet long but will more commonly reach lengths of 5 or 6 feet. They may live as long as 15 years, they are territorial, and may become aggressive if encroached upon.