The remnants of the mighty marshes that once covered the whole coastal plain here are preserved in this 47-sq-km natural park, complete with scenic walking trails and bird-watching observatories, just south of Castelló d’Empúries. The March to May and August to October migration seasons bring big numbers of wading birds. Keen twitchers may glimpse flamingos, purple herons, glossy ibis, spoonbills, rare black storks and more of the 329 species that pass through (82 of which nest here).
There are enough birds to make a visit worthwhile at any time of year. The park's El Cortalet information centre (signposted) is 1km east off the GIV6216 Sant Pere Pescador–Castelló d’Empúries road, halfway between the two towns. If you aren't driving, a summer bus heads along this route from Castelló in July and August only, or it's a pleasant 5km walk or cycle along a path from Castelló.
The centre has wildlife information, maps of trails and two on-site lookout points, hires binoculars (€2.50), and is the trailhead for several walking and biking paths. Follow clearly marked walking trails 1 then 2 (each 2km long) to a 2km stretch of beach (closed April to June). Along the way, you'll pass a spur leading off to Observatori Senillosa, former rice-storing silos that have been converted to lofty observatories for views over the countryside. Elsewhere several hides offer saltwater-marsh views.
Though the paths are always open, morning and evening are best for birdwatching. Take insect repellent in spring and summer.