I have finally put up the bee hotel I made some time ago. It has already attracted a lot of 'guests' over the past few weeks. So far I have only spotted one species of wild bees nesting in it: the red mason bee (Osmia bicornis; rosse metselbij). They have occupied most of the larger holes and reed stems by now (the pictures were taken earlier). I hope it will attract some other species as well over the next few months.
