We define and study cloudoscopy, i.e., exposing sensitive information about the location of (victim) cloud services and/or about the internal organisation of the cloud network, in spite of location-hiding efforts by cloud providers. A typical cloudoscopy attack is composed of a number of steps: first expose the internal IP address of a victim instance, then measure its hop-count distance from adversarial cloud instances, and finally test to find a specific instance which is close enough to the victim (e.g., co-resident) to allow (denial of service or side-channel) attacks. We refer to the three steps/modules involved in such cloudoscopy attack by the terms IP address deanonymisation, hop-count measuring, and co-residence testing.