Kate ScotterPeople still have the chance to snap up free tickets to many of the city's top heritage attractions.Norwich's historic buildings will throw their doors open for free as part of the annual Heritage Open Days from September 10 to 13.Kate Scotter

People still have the chance to snap up free tickets to many of the city's top heritage attractions.

Norwich's historic buildings will throw their doors open for free as part of the annual Heritage Open Days from September 10 to 13.

This year's event is proving to be as popular as ever and although many are now full there are still free tickets left for some of the pre-bookable events.

People still have the chance to learn more about Norwich's twinning links with the Serbian city of Novi Sad at an exhibition of professional photographs and a talk by the Norfolk & Norwich Novi Sad Association, attended by the Lord Mayor and Sheriff, at City Hall on September 10 at 7pm

Tickets are still available for a guide Henry VIII walk organised by St Andrew's Church on September 11 and an escorted tour up St John's Roman Catholic Cathedral Tower at various times on each day of the event.

People can also join a guided tour of the St Giles Rooms, previously known as Norwich Masonic Hall, on September 13.

A new event has been added to the programme, Beating the Bounds, a guided walk about the Georgian parish boundary markers on September 11 at 2pm and September 12 at 6pm.

There are also dozens of events that do not require any booking.

For full details of the Heritage Open Days and how to book, go to www.heritagecity.org/hods or pick up a brochure from tourist information centres, libraries and cultural venues.