Masjid Alwi is another former state mosque that was built during the British Colonial period. Situated in Kangar, the capital of Perlis, the mosque was officiated in 1933 by the Raja of Perlis, Syed Alwi Ibni Al- Marhum Tuan Syed Saffi Jamalullail. Hence, the mosque was named in honour of the Raja. The mosque’s building fund was a concerted effort undertaken by various parties, with contribution from tithe monies and donation from government officials, Muslim traders and the public. Its status as a state mosque was replaced when the new Perlis State Mosque in Arau was built in 1973. In 2008, the mosque was gazetted as a heritage building by the National Heritage Department.
The mosque is strategically located within the town centre of Kangar, neighbouring many government and institutional buildings. Its colonial heritage influence is noted through its onion-shaped dome expressed in the Mughal architectural style which dominates this two-storeyed building. Its main dome is very similar to many other colonial mosques in the country, such as the Masjid Zahir in Alor Setar and the Masjid Kapitan Keling of Pulau Pinang. The main dome is finished with a crescent finial surmounted above it. It sits on an octagonal drum, with a series of rounded windows on the sides.
The rectangular layout is mainly covered by a slight pitch flat roof form, partly covered by a high parapet wall with triangular crenellations. Above the entrance porch, a series of concrete balustrade is arranged across the porch roof, with two attached obelisks like structure or turrets at each corner placed on octagonal bases. The minaret, which is considered an integral feature of a traditional mosque, is placed to the right of the main entrance. It is a typical Mughal-styled minaret, with a chattri style balcony placed
with a pointed onion-shaped dome. Although the pitched roof is absent, the mosque’s building is arranged in tiered layers to indicate its internal spatial arrangement. The central space under the main dome is demarcated by eight sides of pointed arched walls that define the main prayer hall. Ringed by a series of pointed arches, natural day light enter the arched opening of the main prayer hall. To the right of the prayer hall, a group of four, round columns mark the front qibla wall. A mihrab niche is formed by a round arch, while an elevated balcony acts as a minbar pulpit to the far right.