This must be svarga, or the region of the immortals, or the city of Amarāvatī, or the supreme Siddhit thought the Wind-god's offspring Svarga is the region where persons reap the fruit of Jyotishtoma, etc. Siddhi is Illusion spread by Gandharvas.
स्वर्गोऽयं देवलोकोऽयमिन्द्रस्यापि पुरी भवेत्। सिद्धिर्वेयं परा हि स्यादित्यमन्यत मारुतिः॥