One of my very first day-trip adventures after moving to Japan was a visit to Enoshima Island in May 2015. Enoshima holds a special place in my heart and is still one of my favorite spots in Japan. It is relaxing, serene, and offers so much to explore: shrines, caves, boat rides, an onsen/spa, local cuisine, a fish foot bath, a botanical garden, and endless festivals during the summer and fall seasons. On a very clear day, it even offers a great view of Fuji-san.
There are two options via train to travel to Enoshima. The first one is on the classic Enoshima Electric Railway which arrives in the heart of Enoshima city at the Enoshima train station. The other option is to take the Odakyu line to Katase-Enoshima station, which is a closer walk to Enoshima Island.