Several parts combine into one character.

Pictograph: a tall building or watchtower on a high hill, viewed from the side. The encoded meaning: the largest architectural structure visible to ancient observers — where the king lived = the capital city. The single character anchors "capital / metropolis" in CJK historical geography. Identical across 繁體 / 新字体 / 简体.

京 names many of the great cities of East Asia: — Beijing 北京 (Northern Capital — China's capital since the Ming Dynasty in 1421) — Tokyo 東京 (Eastern Capital — Japan's capital since 1868) — Nanjing 南京 (Southern Capital — historic Chinese capital) — Kyoto 京都 (literally "the Capital City" — Japan's capital from 794 to 1868) The directional prefix system (北/南/東/西) plus 京 produces an entire toponymic family.

Mandarin: jīng, level 1st tone. 北京 (Běijīng, Beijing), 南京 (Nánjīng, Nanjing), 京剧 (jīngjù, Beijing/Peking opera — the dominant form of Chinese opera, named after its association with the capital), 京城 (jīngchéng, the capital city), 上京 (shàngjīng, "going up to the capital" — historical phrase for traveling to Beijing).

Japanese: TWO on-readings — キョウ (kyō) and ケイ (kei). キョウ is dominant — 東京 (Tōkyō), 京都 (Kyōto, Kyoto), 上京 (jōkyō, going to Tokyo from elsewhere — a cultural keyword for young Japanese moving from rural areas). ケイ appears in 京阪 (Keihan, the Kyoto-Osaka corridor) and 京浜 (Keihin, the Tokyo-Yokohama corridor — major transportation routes named after their endpoints). Kun-reading みやこ (miyako) is the elegant word for "capital city" — used poetically alongside 都.

Memory aid: a tall building on a hill — where royalty lives.