To add to what's been posted above, you really need to make your wishes clear in a will. You might for example not want to your site to remain live or in some cases your site might have financial value that can be passed on to a named beneficiary.
It is also imperative someone other than yourself has full access to everything required to take ownership of your site i.e. the domain, hosting, software etc. I have seen more than one major site lost forever because of data protection. Those details could be contained within your will or better still (as details may change), with a beneficiary or someone your trust.