Eve is the closest planet to Kerbin and the easiest to reach, requiring the least Delta-V of any planet. Having a similar size to Kerbin gives it a large gravity well and a thick atmospheric composition makes landings easier.
Eve has large oceans of liquid mercury and large, flat continents with a few mountain peaks, and a large crater in the western hemisphere. The surface looks like purple sand dunes.
The atmosphere begins ~100 KM. It is very thick, approximately as thick at 11,500 m, as sea level atmosphere is on Kerbin. One observed deceleration profile is: 130 m/s at 11 KM, 110 m/s at 8.5 KM, 100 m/s at 7.5 KM, 90 m/s at 6 KM, 80 m/s at 4.3 KM.
From within Eve's atmosphere, the sky appears indigo-blue during nighttime. During dawn and dusk, the sky is green. The atmosphere is probably composed of iodine given its purple coloration.
Jet engines function in Eve's atmosphere, but do not provide useful thrust near the surface due to the density of the air.
Eve's only natural satellite is the tiny captured asteroid Gilly in a highly eccentric and inclined orbit.. Gilly's surface is currently bugged, and it is impossible to land there.