Complex sentence: Momin Uddin visited many mosques and gathered lots of information about the mosque architectures, design and calligraphy; in Bangladesh most of the mosques are made of bricks or stones, specially those are built in the Mughal period.
Split into simpler sentences: Momin Uddin visited many mosques and gathered lots of information about the them architectures, including their design and calligraphy. In Bangladesh most of the mosques are made of bricks or stones, specially those built in the Mughal period.