Your own mind.
a temple
A pagoda or a stupa
They believe that the inner-selves is one of the most important places.(i think)
It made it easier for Buddhists to spread their sacred texts.
It is a place for Buddhists to meditate.
Sacred texts are shared between Hinduism and Buddhism, with both religions revering texts such as the Vedas and Upanishads. However, each tradition also has its own distinct scriptures, such as the Bhagavad Gita for Hindus and the Tripitaka for Buddhists.
Mt. Olympus
Hajj is the pilgrimage to Mecca in Saudi Arabia. Hajj means "standing before a deity in a sacred place" or "voyage to a sacred place." Mecca is the most sacred of the Muslim cities.
The majority of the world's Buddhists live in Asia.
Buddhists consider Bodhgaya, in north India the most sacred of all their pilgrimage places. It is here where Lord Buudha realized the ultimate nature of reality, called enlightenment.
I am not sure if you are asking where are most Buddhists or what activities Buddhists undertake, so I will answer both. Buddhism is most prevalent in Asia. It is growing rapidly in Europe and North America. The practice of Buddhism takes place in every action we perform. we use the Buddha's teachings to be mindful of our Body, speech and mind.
The church is an extremely sacred place to any true Christian.