This trip was specifically to see White Rumped and Little Swifts.
From the N340 main highway take the very well marked road to Bolonia, follow through the town/village where provisions can be easily picked up. Continue all the way along the road which can easily be driven by a normal vehicle. You will see on the right an obvious rockface, here I found nesting Griffon Vultures although perhaps a little distant for photography. Also in the area were Bee-eaters. Continue along the road until you find a large rock formation on your left. There is a very obvious picnic area on the right. Park here and view the rockface. There is an obvious very large hole in the rock face where the Swifts were going into. The hole had railings around it and in it, whether these were to protect the swifts was unknown. I had at least 8-10Little Swifts and 4-6 White-rumped Swifts and to add to the White-rumps, House Martins.
Other birds of interest here included Crag Martin, Blue Rock Thrush and much closer, nesting Griffon Vultures. I did not encounter any Red-rumped Swallows here although there were plenty to be seen in Bolonia town.
The road is used by the Military so you can only drive a little further past the Swift site until a barrier is encountered.
I found the best time to see the swifts were before noon or much later in the afternoon. If the birds are not present, don't despair, just give it time and I am sure you will see them. Hope this record is of use.