This massive cathedral, situated across from Rockefeller Center on Fifth Avenue is regarded as the largest Catholic cathedral in the United States. With its two soaring 330-foot spires, St. Patrick's Cathedral is also one of the city's most spectacular architectural sights. Construction on the neo-gothic structure had started in 1850 and completed in 1878. Inside, it boasts of numerous altars and stained glass windows, and a giant organ with over 7,300 pipes. Services are held throughout the day, and many New Yorkers stop in for a moment of serenity in their otherwise hectic lives.