Arashiyama Kyoto Monkey Park is a must visit with kids in Kyoto. You can enjoy a nice climb to see the over 150 macaque monkeys that live on the mountain. The climb takes 30-50 mins depending on physical condition of walkers. You can buy some monkey food and feed them from a reversed cage (humans inside and monkeys outside). For our three days in Kyoto with kids recommendations check here. 

The Arashiyama Kyoto Monkey Park is on Mt Arashiyama. The walk up Mt. Arashiyama is not hard in cool weather, but in hot weather take water and enjoy the rest stops along the way. Wear comfortable shoes and layer clothing between seasons. There is a very old, but fun, playground with a slide at the top of the mountain. The monkeys are at the top where you can also get a great vista of Kyoto City.  Note the path is not advised for strollers (although not impossible). There is a bathroom at the bottom near the entrance and at the top of the mountain.

For a full day combine the Arashiyama Kyoto Monkey Park with visits to the Arashiyama Bamboo Grove and Tenryu-ji Temple, shopping the gift shops and restaurants along the side streets of Arashiyama, and end the day visits to Ryōan-ji to see the beautiful rock garden and Kinkaku-ji(the golden temple).