This is the 1417th most frequent Russian word.
городу
"Dative case of 'город', meaning 'to the city' or 'for the city'."
The dative case 'городу' is used here as it specifies the direction of motion towards the city.
Я отправился к городу, чтобы полюбоваться его архитектурой.
I went towards the city to admire its architecture.
The prepositional sense 'по' governs the dative case 'городу' to express longing or missing.
Я скучаю по городу, где провел свои юношеские годы.
I miss the city where I spent my youth years.
Here, 'городу' appears in the dative case due to the verb 'посвящён,' indicating the recipient of the dedication.