Multi-storied pagodas in wood and stone, and a gorintō
Pagodas in Japan are called tō, sometimes buttō or tōba and historically derive from the Chinese pagoda, itself an interpretation of the Indian stupa. Like the stupa, pagodas were originally used as reliquaries but in many cases they ended up losing this function. Pagodas are quintessentially Buddhist and an important component of Japanese Buddhist temple compounds but, because until the Kami and Buddhas Separation Act of 1868, a Shinto shrine was normally also a Buddhist temple and vice versa, they are not rare at shrines either. The famous Itsukushima Shrine, for example, has one.
After the Meiji Restoration the word tō, once used exclusively in a religious context, came to mean also "tower" in the western sense, as for example in Eiffel tower.
Of the Japanese pagoda's many forms, some are built in wood and are collectively known as mokutō, but most are carved out of stone (sekitō. Wood pagodas are large buildings with either two stories (like the tahōtō, see photo below) or an odd number of stories. Extant wood pagodas with more than two storeys have almost always either three stories (and are therefore called sanjū-no-tō) or five (and are called gojū-no-tō. Stone pagodas are nearly always small, usually well below 3 metres, and as a rule offer no usable space. If they have more than one storey, pagodas are called tasōtō or tajūtō.
A pagoda's size is measured in ken, where a ken is the interval between two pillars of a traditional-style building. A tahōtō for example can be either 5x5 ken or 3x3 ken. The word is usually translated in English as "bay" and is better understood as an indication of proportions than as a unit of measurement.
The stupa was originally a simple mound containing the Buddha's ashes which in time became more elaborate, while its finial grew proportionally larger. After reaching China, the stupa met the Chinese watchtower and evolved into the pagoda, a tower with an odd number of storeys. Its use then spread to Korea and, from there, to Japan.