In reply to Avinash Aujayeb:
Too many brilliant rides to go through them all.
A circuit of the Simonside hills packs a fair bit of punch in to 27 miles -- It used to be my old club's 'Mountain' Time Trial course back in the 60's. You can start and finish anywhere convenient on the route, but our course started at Rothley Cross Roads and tackled the climbs of Coldrife and Garleigh Moor before dropping down in to Rothbury and heading up the Coquet Valley through Thropton when the climbing starts in earnest. There's the innocuous looking sod of 'the one before Billsmoor', then Billsmoor, before dropping down to Elsdon then climbing the Gibbet. From there a fast and exciting straight road ( with some severe dips) leads mostly downhill towards Rothley.
For a longer ride you could always follow the Tyneside Vagabonds 'Mountain' course that started in Rothbury and followed the main road through Belsay, over the Ottercops to Elsdon, before reversing the above route and finishing in Ponteland. About 67 miles!
For an epic you could always do the Tynemouth, Newcastle, Corbridge, Hexham, Carts Bog, Whitfield, Alston, Nenthead, Killhope Moor, Stanhope, Crawleyside, Edmundbyers, Carterway Heads, Shotley Bridge, Gateshead, then back to the start at Tynemouth. 120 miles and it takes you over the highest 'A' road in Britain at 2056 ft above sea level. Think I was about 18 when I did that one on a steel bike with only 12 gears 52/46 on the front and 13 - 26 on the back.
Enjoy.