Above: The author, 15th. great grandson of Abraham Senior, at the entrance to his house in Segovia, now the "Centro Didáctico de la Judería" (Jewish Educational Center).
Note the logo representing the initials of Abraham Senior.

Below: The "secret" synagogue of Abraham Senior - Left: the women's section.

Apparently the original room had no windows to prevent passers-by from seeing the family at prayer.
The room was ventilated by openings at floor level.