Marker for the Exploratorium Department of Operations’ electrical junction box shown in the concrete floor which houses a radiant heating and cooling system. (Photo by Mignon O’Young)
![Marker for the Exploratorium Department of Operations’ electrical junction box shown in the concrete floor which houses a radiant heating and cooling system. (Photo by Mignon O’Young)](https://gabreport.com/wp-content/uploads/2014/03/DSC03718.jpg)
Marker for the Exploratorium Department of Operations’ electrical junction box shown in the concrete floor which houses a radiant heating and cooling system. (Photo by Mignon O’Young)