The word "万里迢迢" is formed by combining the literal distance measurement "万里" (ten thousand li, indicating a great distance) with the reduplicative descriptive term "迢迢" (meaning far away), thereby creating a compound that intensifies the concept of being extremely distant.
Word Definition - 万里迢迢
wàn lǐ tiáo tiáo(adverbial phrase used with verbs such as 歸|归[guī] or 赴[fù] etc) traveling a great distance