Neilson Hays Library

It occupies a historic building on Surawong Road in Bangkok's Bang Rak district, designed in neoclassical style by Italian architects Mario Tamagno and Giovanni Ferrero.

The building, completed in 1922, features a symmetrical plan, with a domed rotunda originally serving as the entrance hall (now a gallery) and an H-shaped reading room.

After Jennie's death, Thomas Hays commissioned Mario Tamagno, an architect from Turin, Italy, to design the library.

Other buildings that Tamagno contributed to include the Ananta Samakhom Throne Hall, Phaya Thai Palace, and the Hua Lamphong railway station.

The Neilson Hays library won the ASA Architectural Conservation Award from the Association of Siamese Architects in 1982.