Seen last weekend (31-1-09) were Czechoslovak AF MiG-21F-13 0210 and the nose of Polish MiG-21PFM 6510. They are both outside and easily visible on the Belkmerweg 109, one on each side of the house.
From the N9 take the Zeeweg towards the coast (the only road in that direction in St. Maartensvlotbrug, which is a very small village). Take the first to the right, this is the Belkmerweg. The house with the aircraft is on your left after some 1300 m (I am 99% sure this is the exact spot: 52 47 56 N, 4 42 29 E).
There is a dog in the garden, but that's very friendly (unlike its looks....).
Happy hunting!