Mulu’s Deer Cave is the second largest cave in the world, with a chamber which could fit up to 40 Boeing 747 airplanes inside it. One of the most intriguing features of the Cave is at its southern entrance - if you look from a particular angle, one side of it resembles the profile of Abraham Lincoln! Deer Cave is home to various species of bats whose nightly exodus can be witnessed at dusk on days when the weather is fine.