Sinus infections usually begin with the symptoms of a cold (for example, a runny nose, occasional cough and/or mild fever), and then develop into pain and pressure in the sinus cavities. About 7 to 10 days after initial cold-like symptoms other symptoms develop that suggest you may have a sinus infection.
The Ruins of Sescheron. The Ruins of Sescheron are available in the Adventure Mode of Diablo III. Specifically in Act III, near the Arreat Crater. They were released as part of patch 2.3. The area is designed to have a melancholy feel to it, with elements such as funerary art and pyres.
Along with Kanai's Cube, patch 2.3 also added the dungeon Ruins of Sescheron. This dungeon appears around the Arreat Crater, in Act 3. You must be playing Adventure Mode. If you clear the dungeon, you will gain access to the Tomb of King Kanai, where you will find Kanai's Cube.