Walk along the Backs, and turn right down Garret Hostel Lane until you're standing on Garret Hostel Bridge.

At this point, the surface of the River Cam flood plain is about 4m above sea level, and the bottom of the river is only about 2m above sea level, yet the sea is almost 50 miles (80km) to the north at King's Lynn. It's only Jesus Lock, Bates Bite Lock, and Denver Sluice that keeps the salt water from reaching Cambridge and making the River Cam tidal!

Boreholes have been drilled under the Cam at Garret Hostel Bridge and a deep buried channel was found which goes down to at least ten metres below sea level. This channel was cut about 14,000 years ago at the end of the last Ice Age when the ice sheets receded from the Wash and southern North Sea. It was almost as though someone had pulled a plug from a sink and the water drained to cut out this new course, which the present day River Cam has inherited. The river has hardly moved from that Ice Age course and has simply filled up the channel, first of all with peats and later with floodplain silts and clays, which began forming about 2000 years ago in the Romano-British period.

Go over the bridge and turn left once you reach Trinity Lane. Keep walking along Trinity Lane until you reach Trinity Street - where you will see a row of shops. Turn left and walk along Trinity Street and St John's Street.

Henry VIII stands above Trinity College

You will pass Trinity College on your left. Above the grand entrance you will see a statue of Henry VIII... Look closely, can you see anything odd about what he's holding in his right hand?

As you face Trinity College, you'll see a small apple tree in a grassy area to the right. Some people alledge that this tree is grown from the seed of the apple tree that Isaac Newton sat under at his manor house somewhere near by!

You will also pass by St John's College and the grand entrance on your left. St John's College was founded by Margaret Beuford who was Henry VIII's grandmother, she also founded Christ's College and they've got similar crests. As you look above the gates and the crest you will see little white daisys carved into the stone which are there because the other name for daisy is margarite - so it's a play on her name!

If you look very carefully at the flowers you can see the tail of a fox disappearing into a hole with a white swan or goose... the original craftsman or designer was probably having a little joke!

Turn left at the end of St John's Street, at the Round Church, and walk up Bridge Street towards the Quayside.