堡

an earthwork / castle / position of defense / stronghold / used in place names, often as phonetic bao for "burg" or "bad"

variant of 鋪|铺[pu4] / used in place names

Bulgaria / Bulgarian / abbr. for 保加利亞|保加利亚[Bao3 jia1 li4 ya4]

Tu (ethnic group) / surname Tu

earth / dust / clay / local / indigenous / crude opium / unsophisticated / one of the eight categories of ancient musical instruments 八音[ba1 yin1]

to defend; to protect; to keep / to guarantee; to ensure / civil administration unit in the baojia 保甲[bao3 jia3] system (old)

Islamabad, capital of Pakistan

Luxembourg

ancient castle

Constantinople, capital of Byzantium

Istanbul (Tw)

Brandenburg (e.g. gate, concertos)

Ekaterinaburg or Ekaterinburg (formerly Sverdlovsk), Russian town on the Ural mountains

Pittsburgh (Pennsylvania)

Gutenberg (name) / Johannes Gutenberg (c. 1400-1468), inventor in Europe of the printing press / Beno Gutenberg (1889-1960), German-born US seismologist, coinventor of the Richter magnitude scale

Project Gutenberg

Wubu County in Yulin 榆林[Yu2 lin2], Shaanxi

Yekaterinburg (Russian city, also known as Ekaterinburg or Sverdlovsk)