Something About Giants (in England!)

Big?  Yes.  Friendly?  Unknown.

Here's a bit more about Gog and Magog from a few weeks back (the clock jacks from The Lamp from the Warlock's Tomb (1988)), since I was curious about their history in London.  The Londonist explains a bit of their back story:

Gog and Magog (or confusingly Magog and Cornelius) were two monstrous giants, the product of the 33 wicked daughters of Roman emperor Diocletian and certain demons they'd been canoodling with.  As he founded New Troy (which would become London), the heroic Brutus tamed the two colossi, forcing them to serve as guardians of the city by chaining them outside his palace, the site of which is now Guildhall.  Of course, the tale is nonsense, but somehow the legend lived on, and the duo continued to be associated as the city's guardians.  The effigies of 'Gogmagot the Albion' and 'Corineus the Britain' were recorded as appearing at the coronation of Elizabeth I in 1558 (where exactly, it isn't clear),

But these two aren't the only two giants in British mythology.  The English Heritage blog tells of the brothers Goram and Vincent from the Bristol area:

Each fell in love with the beautiful giantess Avona, the river's namesake. They competed for her love by trying to drain a lake, creating huge drainage channels which became the Avon Gorge and Hazel Brook in Henbury.  Goram, heartbroken at losing the contest, stamped his foot in anger, creating the impression known as the Giant's Footprint in Henbury gorge, before drowning himself in the Severn Estuary.  The contours of his corpse became the two islands of Steepholm and Flatholm.

Even Stonehenge isn't immune to having been influenced by giants:

According to Geoffrey of Monmouth's 12th-century History of the Kings of Britain, Stonehenge was originally brought from Africa to Mount Killaurus in Ireland by giants.  Its magical stones had healing properties, and the giants built a bathhouse amid the stones to cure illness.  Geoffrey suggests Merlin transported the stones from Ireland to their current location on Salisbury Plain at the behest of Aurelius Ambrosius to mark the graves of slaughtered British noblemen.

Quite how Merlin managed this is not made clear by Geoffrey, who states enigmatically that Merlin used his own 'contrivances' (machinationes) to transport the stones.  However, an illustration in a 14th-century manuscript of the Brut, an adaptation of Geoffrey's history, seems to show Merlin in the temporary form of a giant helping to reassemble the stones.