Marble Arch W1

Still Water is a 30ft high horse's head in bronze by horse sculptor Nic Fiddian-Green. It was installed in 2011 to replace a similar but slightly smaller work, Horse at Water, which had been on loan from Sir Antony and Lady Bamford.
It has an amazing presence. Even from behind (whatever 'behind' means in this context),

Boy and Frog, Queen Mary's Gardens NW1

The Boy and Frog is a delightful bronze by Sir William Reid Dick in 1936. It was donated to the park by rich artist Sigismund Goetze, who lived close by.
The statue was placed in the gardens when they were laid out in the 1930s after the departure of the Royal Botanical Society.

Triton Fountain, Queen Mary's Gardens NW1

The Triton Fountain was made by William McMillan in 1950 to commemorate the artist and philanthropist Sigismund Goetze, who lived and worked in Grove House (now Nuffield House) close by. His wife was the founder of the Constance Fund which donated fountains in Green Park and Hyde Park.

Triton - half man, half fish - was the son of Poseidon and Amphitrite. He was the sea-god's herald, blowing his conch shell so mightily it could calm or raise the sea and put giants to flight.

Triton is accompanied by a couple of mermaids, who have divided tails in the way that brought so much prudish disapproval on Starbucks they had to change their original logo.

Pie Corner, Cock Lane EC1

The Golden Boy of Pie Corner marks the point where the Great Fire of London of 1666 finally burnt out. 

The fire started in Pudding Lane and though Pie Corner probably got its name from a pub called the Magpie, local wags joked that it was a punishment for the deadly sin of gluttony. Today, some seem to think that our forefathers meant this to be taken seriously, which is a terrible slur on the sense of humour of the folk that included Congreve, Etherege and Aphra Behn. They took the Catholic conspiracy theory very seriously, however.

The Golden Boy was carved in the early 18th century by a signmaker called Puckridge in Hosier Lane and placed over the door of the Fortunes of War tavern in Giltspur Street. He was painted, not gilt, and the inscription now seen on a stone plaque was inked on his chest.
The pub was demolished in 1910 but the Fat Boy delightfully still marks the spot where the fire died out.