This well-put-together dinosaur park in Réclère features a 2km-long footpath winding through woods past 45 different life-size prehistoric creatures lurking between trees. Beneath the park lies the caves of Grottes de Réclère. Kids love it, especially when you tack on the opportunity to spend the night in a yurt (Sfr30 plus per adult/child Sfr26/18). A range of other accommodation is available; see the website for details.
To get here, take bus 78 from Porrentruy station in the direction of Fahy and get off at stop Chevenez, place la Grangette, where you'll need to change to bus 73, bound for Damvant and alight at stop Réclère, Les Grottes (Sfr13.20, 40 minutes). Otherwise, rent a car and drive.