This is actually a combination of two temples one dedicated to Lord Vishnu and the other to Lord Shiva. In local language Sas-Bahu temple means mother-in-law and daughter-in- law temple.
The story goes like this; Once upon a time there was a queen at Gwalior who was an ardent devotee of Lord Vishnu and she built a temple to Lord Vishnu in the form of Sahasrabahu (Lord with thousand hands). But, when her son got married her daughter-in-law was an ardent devotee of Lord Shiva so the queen built another temple adjacent the Vishnu temple for Lord Shiva worship. Thus this temple complex together came to be known as Sas-Bahu temple.
However, please note that there are many others who feel this story baseless. According to them Sas-Bahu is only the aberration of the name Sahsra Bahu.
The temple dedicated to Lord Vishnu is an example of temple architecture of the region.
Temple is within the Gwalior fort complex.