Srimad Bhagavatam Canto 10, Chapter 76, Text 07

SB 10.76.7

tatheti girisadisto
 mayah para-puram-jayah
puram nirmaya salvaya
 pradat saubham ayas-mayam
 
Translation: 
 
Lord Siva said, “So be it.” On his order, Maya Danava, who conquers his enemies’ cities, constructed a flying iron city named Saubha and presented it to Salva.
Srimad Bhagavatam Canto 10, Chapter 76, Text 06
Srimad Bhagavatam Canto 10, Chapter 76, Text 08