Kuan Yin Temple

Kuan Yin Teng, or Temple of the Goddess of Mercy, is one of the oldest temple ever built in Penang. It is located along Jalan Masjid Kapitan Keling, formerly Pitt Street. The temple honours Kuan Yin, a devout Buddhist who was said to have attained the coveted state of Nirvana but had chosen, instead to remain on earth in order to provide guidance and help to those who are themselves striving to reach Nirvana.

The Kuan Yin Teng offers the best experience of seeing a Taoist temple in action. It is one of the busiest temples within the Inner City of George Town. There are beautiful architectures like the dragon-entwined pillars, carved from a type of green stone, which support the temple's high roof, and the statue of Kuan Yin, located in an inner chamber.

Kapitan Keling Mosque, Penang

I am not too sure if non-Muslims are allowed in the mosque grounds.
Below are some info of the Kapitan Keling Mosque:
The Kapitan Keling Mosque is Penang’s first-ever mosque built in the 19th century. This is the largest historic mosque in George Town, founded around 1800. A monumental structure surrounded by low walls and crowned with Moghul-style copper domes, the mosque was named after the head of the Indian Muslim community back then, Cauder Maydin Merican. It was originally built as a rectangular building with verandahs and a hipped roof and had been enlarged several times. British architects commissioned by the Muslim and Hindu Endowments Board gave the mosque its British Moghul Revival appearance in 1916.