Why stop here:
The palace used to be the residence of imperial wives and consorts of both the Ming and the Qing emperors, as were other courtyards lying respectively in the east and west of the Inner Court (Nei ting). A fire destroyed the entire courtyard except the gate in 1845, a couple of years after the Qing Empire's defeat in the First Opium War with Britain and the signing of the Treaty of Nanking. It was not until 1909 that the Qing court decided to renovate the dilapidated courtyard. The new hall was a three-storey western-style building dubbed the "Crystal Palace" because of its steel frame and glass walls standing in a fish pond which was to be filled with water for viewing the swimming fish from inside the basement. Yet it was never completed. In 1917 the northern part of the courtyard was bombed from the air during the warlord conflicts spreading across China. After the founding of the Palace Museum in 1925, two-storey storehouses to accommodate the museum collection were built around the Crystal Palace in 1932. The Palace of Prolonging Happiness went through a checkered history in the early twentieth century, and is now home to exhibition galleries.
As you exit the Palace of Prolonging Happiness through the Gate of Deep Green Thunder (Cangzhen men) at the end of the east entrance way, lying in front of you is a long corridor with high vermillion walls on both sides. As you pass through it, you are highly recommended to take a few snapshots, especially on clear days, to document the impact of the red walls against the blue sky. The corridor leads to the entrance to the Qianlong Garden and the Treasure Gallery where the imperial collection of treasures and extant palace paraphernalia are displayed. An extra charge of 10 yuan is required.