We were there in the winter, in February. It was nice, you can choose if you want to go up by elevator or if you want to walk by stairs. Upstairs there is a nice view but there is a glass, so not so nice photos because if that. Lots of people even in winter. In front of the gate you can buy some refreshments. It would be better to visit in summer,because of the gardens with roses. And maybe interesting to visit at night because there is observatory near Petrin.