Matsu's temples are pretty small by Taiwan standards, which isn't surprising given the population is less than 10,000 and flat land is at a premium. Several shrines are dedicated to Baimazunwang (白馬尊王, 'the honourable white horse king"). This minor god - human, not animal, in case you're wondering - is virtually unknown in Taiwan itself.
The photo at the top shows a Baimazunwang temple on Nangan. The other image shows a discarded censer beside the same temple.