Somerset House lays on a couple of free guided tours every week, which are well worth doing.
This short one hour tour will show you some of the graceful staircases in the West Wing and the atmospheric Deadhouse, and introduce you to some of the Tudor intrigues that took place in the Strand mansion.
You'll also learn about about British naval power, see some interesting scientific curiosities, and get a taste of the extravagant entertainments laid on during the Georgian period.
If you're more interested in the personalities then you might like to try the Old Palace Tour of Somerset House instead, which concentrates on the building's Royal connections.
Old Palace Tour at Somerset House – Every Tue – The Old Palace Tour will introduce you to three Stuart queens who had an association with the old buildings at Somerset House
Good Grief, Charlie Brown! – 25 Oct 2018 to 3 Mar 2019 – Fans of Charles M Schulz much-loved Peanuts cartoon will want to see the Charlie Brown and Snoopy exhibition at Somerset House.
Guided walk around Charles Dickens’ London – Every Fri – This guided walk will take you around some of the most memorable streets and locations that Charles Dickens used in his novels.
11 — London’s cheapest sightseeing bus – Every day – If you don't fancy spending 25-30 pounds on an open-top sightseeing bus, then there's a much cheaper alternative — the No 11 bus.
City Highlights: The Top 10 sights – Every Mon, Wed and Sun – A two-hour guided walk around the Square Mile, showing you some of the most famous historical sites and buildings in the City of London.
Mansion House: The Lord Mayor’s Residence – Every Tue – Look inside the Lord Mayor of London's official residence at Mansion House and see the interior courtyard and famous Egyptian Hall.
Guided tour of Wren’s best churches – Every Tue and Thu – This guided walk will look at the outside of St Pauls Cathedral and at a selection of Christopher Wren's finest City churches
Look for more guided tours in January
Here are some more free events in London if you want a cheap day out
Disclaimer: Event details can change at short notice and you should reconfirm everything before making plans