The "60 van Texel" (The sixty of Texel) is organised every other year on Easter Monday since 1991 on the Dutch island of Texel. There are main 2 distances, the 60km (37 miles) which is a clockwise loop around the entire island and the 120km (75 miles, since 1993), an anit-clockwise and clockwise loop around the island. The 60km distance can also be run as a relay team of 4.
The 60k loop around Texel takes you along nature reserves, dunes, stretches of beach, trails and long straight roads along dikes. A very flat race with a "killer climb" at the end when you'll have to conquer the Hoge Berg (Dutch for high mountain), a staggering 16 meters high. Only 12km of the route are on the beach, which makes this in essence a road race.
Some barefoot runners managed in the past to complete the 60K without any foot protection but there are some stretches with nasty underground (see slides 240 and 321) There are a total of 11 aid stations, with the addition that at the start location it is possible to hand over to the organization private stuff like special drinks, clothes or shoes to transfer to posts 3 (16,9 km), 6 (29,7 km) and 9 (45,2 km).
Most runners stay over on the island the night before, during which the organisation give final race information and provides a seminar. The start is in the southeast corner of the island (near the ferry terminal) and the route then goes west towards the 1st beach section starting at ~5.5km till 13, followed by a road section through the forrest and another 4.5km long beach section, then a packed trail through the dunes, a bike path up to the lighthouse, the turning point and the east coast of the island along the dike, via the villages of Oosterend and Oudeschild, to the final hill and a finish in the town of Den Burg.
Subscription for the 2017 event (17th of April) is full, but here is a link (in Dutch) to a forum where people exchange racenumbers (starting proof or "startbewijs" in Dutch).
Some videos from previous years: