This year's Heritage Open Days scheme will see over 3,000 buildings across England open their doors free of charge from Thursday to Sunday.
It is the public's annual opportunity to see inside properties which are normally closed or charge for admission.
Last year Tyne and Wear was the second most active area for visits in the country.
In 2002 there were 84 participating buildings, tours and events in Tyne and Wear for Heritage Open Days, which generated 19,500 visits.
In 2003 that rose to 112 and 26,000 visits and in 2005 28,000 visits. This year there will be 181 buildings, tours and activities.
For Tyne and Wear events click on www.twhods.org.uk
The region's top heritage sites opening free on September 9 are:
NORTHUMBERLAND: Alnwick Castle; Belsay Castle and Gardens; Brinkburn Priory, near Rothbury; Cherryburn, near Stocksfield, birthplace of Northumbrian artist and engraver Thomas Bewick, free also on September 10; Chesters Roman Fort, Chollerford; Corbridge Roman Town:
Cragside, Rothbury; Dunstanburgh Castle; Etal Castle; George Stephenson's Birthplace, Wylam; Housesteads Fort:
Lindisfarne Priory; Prudhoe Castle: Wallington, Cambo; Warkworth Castle.
TYNE AND WEAR: Gibside, Rowlands Gill; Holy Jesus Hospital, Newcastle, also free on September 10; Tynemouth Priory.
COUNTY DURHAM: Barnard Castle.
Other open events taking place across the region include the 1913 Harbour Commissioners' Offices in Blyth, Seaham North Dock, and Redhills Miners' Hall, Durham.