Nelson's Column

Nelson's Column was a monument in Trafalgar Square, London. It consisted of a column, over one hundred fifty feet tall, and a seventeen-foot-high statue of Horatio Nelson on top of that.

On 23 October 1843, the Fifth Doctor climbed the column and confronted two Sevakrill who had taken over the bodies of the columns builders: Samuel Morton Peto and Thomas Grissell.

They had built a missile inside the column and planned to detonate it in 2017, destroying the Earth and distracting the Charnal horde, whom they were at war with. To protect this operation, they had several stone lions, hidden by perception filters, patrol the area. The Doctor managed to appeal to Peto and Grissell and they broke free.

The Doctor spent two weeks lowering the missile into a shaft beneath column and building a floor to cover it. By this time it was November, and the statue of Nelson was being added when the Doctor departed. (ST: The Lions of Trafalgar)

After materialising around Nelson's Column, the Monk had the Doctor's TARDIS take on the appearance of the Statue of Liberty. (NA: No Future)

A Dalek patrol passed the column while chasing Barbara Wright, Dortmun and Jenny. (DW: The Dalek Invasion of Earth)

The Ninth Doctor landed a spaceship next to the column, and apparently no one noticed. Rose was there. (DWM: The Love Invasion)

In a timeline where the Daleks exterminated humanity in 1963, Nelson's Column, along with London and presumably the rest of the world, was in ruins. When the The Doctor and Amy arrived in the Square in 1963, the Doctor's TARDIS landed next to the statues toppled head. The timeline was restored when the TARDIS crew travelled to Skaro to destroy the Eye of Time. (VG: City of the Daleks)