The Milan Cathedral (Duomo di Milano, in Italian) is the largest church in Italy, with an internal height of about 45 m (148 ft), has the highest Gothic vaults of a complete church. Construction began in 1386, and was completed only in 1965. The roof of the Cathedral with her Gothic spires is open to tourists (for a fee) and you can admire all Milan city centre.
The Cathedral has a LED lighting system, the night view from the square is a must.
On the top of the highest spire a golden statue of the Virgin Mary is placed. Called "Madonnina" (little Madonna) is symbol of the city and beloved by Milan people.
Dedicated to this statue is a popular song composed in 1934 (Oh mia bela Madunina - Oh my beautiful little Madonna) by Giovanni D'Anzi, that became in few years the unofficial anthem of Milan.
Useful & Interesting Links:
Milan Cathedral Official Website
https://www.duomomilano.it/en/
Song "Oh mia bela Madunina" and views of the Cathedral
https://www.youtube.com/watch?v=aDrXOiqHPS4