Bach Ma -- with more than 20,000 hectares (49,400 acres) of high mountain trails and sweeping valleys -- was once a playground for the French, who built villas on these mountaintops to stay cool when on holiday from Hue. You'll see a number of ruin sites, mostly the remnants of small French resorts and secluded cabins. The park is humid and rainy year-round, but the high elevation (1,712m/5,617 ft. at its peak) makes for cooler temperatures (bring a light windbreaker). The best time to go is in March and April, when the rhododendrons bloom. Entrance to the park is just 10,500 VND, 5,500 VND for students, and fees for hiring a jeep to take up the rocky track to the park's pinnacle start at 350,000 VND. There's a network of well-marked trails (though nobody has a map), and some cozy lodging at the top. You can hire a guide at the park office for hiking. The park is on the road between Lang Co Beach (at the northern end of the Hai Van Pass) and the town of Hue. Many make this a full afternoon before carrying on to Hue, with an overnight in Lang Co, or heading over the hump to Danang or Hoi An. For details, contact (or show up at) the Ecotourism and Environmental Education Center at the base of the hill (the entrance is well marked from Hwy. 1; tel. 054/3871-330; fax 054/3871-329; The park office is open daily from dawn to dusk.