Large crowds, poor crowd control. Fee for picture-taking anywhere within the palace. Palace dates from the 7th century, with Dalai Lama V, and was used continuously until Dalai Lama XIV left after the Chinese invaded in 1950. Very dark inside - murals obviously darkened by many years use of yak butter lamps for illumination.
Current illumination is by sparsely scattered electric lights - mostly fluorescent.
More care and energy seems to have gone into the complex system of infrared and video security systems. The largest was said to contain 110,000 lbs of gold. One room alone contained about six of these. Tibetan books consist of stacks of thin sheets, maybe 10cm by 50-60cm, loosely bound by tied cords through holes in one end. The libraries contained thousands of these scriptures, some wrapped in protective cloth, others stacked on open shelves.