Why add a word under the Beijing word in Nanjing Station?

Beijing has its own variants (like the ancient capital Beijing), and the art of calligraphy pays attention to individuality and cultural connotation. It is understandable to write some variants of ancient Chinese characters.

Calligraphy is still commonly used now, but it was used less in Beijing before.

Beijing, the original meaning: artificially built high mounds. Shuowen is extremely high (extremely high, very high)