here is somes info I've read recently : just south-west of Thessaloniki, there are the aliakmon, gallikos and axios delta with glossy ibis, purple heron, wader, slender-billed gull, one pair of white-tailed eagle, pratincole, tern, penduline-tit, sometimes pelican and pygmy cormorant...wilson's phalarope and pectoral sandpiper were seen there in 2007.
Further south, there are the alikes kistrous kitrous saltwork (10km NE of Katerini) good for wader, slender-billed gull and other bird
There is an access to Mont olympus via litochoro but you have to walk 6km to the refuge and 5 more km to the summit. between the car park and the refuge, black, middle-spotted, three-toed, white-backed and grey-headed woodpecker are present in the forest but are rarely seen. there are also rock bunting, crossbill, crested tit,...
near the refuge, you can seen alpine choughs and accentor. lammergier was present in the past but has not been seen recently.
The walk to the summit is a very good spot for wallcreeper + alpine accentor, alpine choughs and alpine swift. Griffon vulture and lanner falcon can be seen.
Check the trip report for more info on the spot and sightings
FD