莅临 (lì lín) is a very formal verb used only when a distinguished person (leader, official, honored guest) arrives, especially to inspect or attend an event. It is more formal and specific than 光临 (guāng lín), which is polite but used broadly for customers or visitors. Unlike neutral verbs like 到 (dào) or 到达 (dào dá), 莅临 carries deep respect and is never used for oneself or casual visits.