A great idea is to rent a bike to ride to the sea. There is a green path very well built that follows the track of an old rail way. It goes from Olot to Girona, and from Girona to Sant Feliu. It is very well marked and easy to follow. Here are the links:
A great idea is to avoid the return by taking the bus back. Teisa serves all these destinations. Olot is up the mountains, so you probably will want to take the bus there and ride down, while Sant Feliu is great all the way down to the sea, a paella and then a peaceful return with the bike on the bus.
A place to rent a bike very near the apartment is Girona Cycle Center. They are very good professionals, they rent any type of bikes and qualities.
Another idea is to use an electric bike: burricleta. Unfortunately they are not in Girona but if you have a car they have rent them in very nice surroundings, about 40 minutes ride from Girona.
