Pastel de Nata. It’s a Portuguese egg tart pastry that is somewhat the national pastry in Portugal.

I took a quick snap of the pastries while lining up at Pastéis de Belém.
The first time I had these pastries was in Macau many years ago, finally I had a chance to try the original ones in Lisbon.
My advice: Don't leave Lisbon without trying these delicious egg tarts.

The History (since 1837)