Butterfly Park Empuriabrava is a warm, planted butterfly house on the edge of Castelló d'Empúries and Empuriabrava. Inside are free-flying butterflies and other tropical animals, making it an easy bad-weather or family stop near the wetlands of Aiguamolls de l'Empordà.
It is modest in scale, but the controlled tropical setting makes it different from the surrounding medieval town and marshland sights. Allow an hour or so, and combine it with the eco-museum or the nearby old town rather than making a special long detour.