A couple weeks ago, reports in Austria claimed that Chelsea will be playing the preseason curtain-raiser at Rapid Wien's brand new stadium on July 16th, after which the Blues would decamp to Velden am Wörthersee for a brief training camp. This is the same place in southern Austria that Chelsea used in 2014 to prepare for the season. That was a two-week stay, with friendlies all around the region, including a visit to Hungary and Slovenia.
This year, it appears that our stay will be a bit shorter. According to Kleine Zeitung, after the Rapid Wien friendly, in the "third week of July" Chelsea will open a week-long training camp at Velden, which will once again include a friendly against local side Wolfsberger AC (i.e. the lovingly named RZ Pellets WAC) on July 20th, a Wednesday.
WAC have confirmed both the friendly and the week-long training camp on their official website. Chelsea have yet to confirm either friendly or the training camp itself, but all signs point to that being a formality at this point.
In 2014, a true football hype was triggered in Carinthia by Chelsea. The game against WAC was the first football game at the Wörthersee Stadium that was sold out since Euro 2008. Hundreds spectators and journalists also besieged the Falkensteiner Schlosshotel Velden to catch a glimpse of the stars.
[Chelsea] will travel on 16.07.2016 to Carinthia and return to their quarters at Falkensteiner Schlosshotel Velden from 07.17.2016 until 07.23.2016. Training will be back in the Forest Arena in Velden or the Wörthersee Stadium in Klagenfurt. The ideal climate and the perfect conditions [...] in 2014 have significantly contributed to Chelsea's decision.
-source: RZ Pellets WAC