In an exhibition off the main courtyard, a large panel urges worshippers to "promote unity" and "oppose division", quoting both the Koran and traditional Chinese thinkers. Passages of the Koran can still be seen inside the mosque, and the prayer hall is unchanged.
"It does not look completely Chinese, nor foreign", says a local resident. Instead, it reminds him of the imposing government building that hosts Communist party congresses in the centre of the capital: "It looks a bit like the Great Hall of the People."
Many locals at the Doudian Mosque, as well as Chinese Muslims approached for interviews, declined to speak or asked to remain anonymous for fear of government reprisal.
What happened to their communities has been repeated across China, with hundreds of mosques modified over the past five years. Satellite imagery shows at least 1,714 buildings have been altered, stripped or destroyed. The government says the changes are to modernise the mosques and "harmonise" them with Chinese culture.
Such modifications have been most prevalent in regions with the highest population of ethnic groups that traditionally practise Islam. In the western region of Ningxia, satellite analysis shows that more than 90 per cent of mosques bearing Islamic architecture have had features removed. In the northwestern province of Gansu, the figure is over 80 per cent.
