The authors propose a method to compute the boundary stress tensor for a gravitating system in asymptotically anti-de Sitter (AdS) space, addressing ambiguities present in previous attempts. Their definition correctly reproduces the masses and angular momenta of various spacetimes and is interpretable as the expectation value of the stress tensor in a quantum conformal field theory (CFT) via the AdS/CFT correspondence. They demonstrate that the conformal anomalies in two and four dimensions are recovered, with the two-dimensional stress tensor transforming as expected under diffeomorphisms. For global AdS$_5$, they find a nonzero ground state energy that matches the Casimir energy of the dual $N = 4$ super Yang-Mills theory on $S^3 \times R$. The paper also discusses the challenges and prospects for defining a quasilocal stress tensor in asymptotically flat spacetimes.The authors propose a method to compute the boundary stress tensor for a gravitating system in asymptotically anti-de Sitter (AdS) space, addressing ambiguities present in previous attempts. Their definition correctly reproduces the masses and angular momenta of various spacetimes and is interpretable as the expectation value of the stress tensor in a quantum conformal field theory (CFT) via the AdS/CFT correspondence. They demonstrate that the conformal anomalies in two and four dimensions are recovered, with the two-dimensional stress tensor transforming as expected under diffeomorphisms. For global AdS$_5$, they find a nonzero ground state energy that matches the Casimir energy of the dual $N = 4$ super Yang-Mills theory on $S^3 \times R$. The paper also discusses the challenges and prospects for defining a quasilocal stress tensor in asymptotically flat spacetimes.