Van Hove singularities (VHSs) in twisted graphene layers have been observed using scanning tunneling spectroscopy (STS). These singularities, which arise from the divergence in the density of states (DOS) in two-dimensional materials, can be tuned by rotating stacked graphene layers. This rotation brings the VHSs closer to the Fermi energy (E_F), enabling the study of electronic instabilities that can lead to new phases of matter, such as superconductivity, magnetism, or density waves. In single-layer graphene, the VHS is too far from E_F to be easily reached with standard doping or gating techniques. However, by rotating the layers, VHSs can be induced within the range of E_F achievable via gate tuning. In twisted graphene layers, the electronic band structure leads to a saddle point, causing a divergence in the DOS, known as a VHS. When E_F approaches the VHS, weak interactions are amplified, leading to instabilities. The study shows that by rotating the layers, the VHSs can be controlled, allowing for the tuning of E_F and the VHSs. This provides a powerful tool for manipulating electronic phases in graphene. The experiments reveal that the energy separation between VHSs (ΔE_vhs) depends on the rotation angle. For a rotation angle of 1.79°, ΔE_vhs is approximately 82 meV, while for a smaller angle of 1.16°, it is about 12 meV. The results are consistent with theoretical predictions and show that the VHSs can be controlled by adjusting the rotation angle. The study also highlights the importance of interlayer coupling in forming VHSs, as vanishingly small interlayer coupling prevents their formation. The findings demonstrate that in graphene, unlike in other materials, the position of VHSs can be tuned by controlling the relative angle between layers. As the VHS approaches E_F, a strongly localized charge-density wave (CDW) appears, indicating the potential for inducing and exploring correlated electronic phases in graphene. This work opens new avenues for the engineering of electronic phases in two-dimensional materials.Van Hove singularities (VHSs) in twisted graphene layers have been observed using scanning tunneling spectroscopy (STS). These singularities, which arise from the divergence in the density of states (DOS) in two-dimensional materials, can be tuned by rotating stacked graphene layers. This rotation brings the VHSs closer to the Fermi energy (E_F), enabling the study of electronic instabilities that can lead to new phases of matter, such as superconductivity, magnetism, or density waves. In single-layer graphene, the VHS is too far from E_F to be easily reached with standard doping or gating techniques. However, by rotating the layers, VHSs can be induced within the range of E_F achievable via gate tuning. In twisted graphene layers, the electronic band structure leads to a saddle point, causing a divergence in the DOS, known as a VHS. When E_F approaches the VHS, weak interactions are amplified, leading to instabilities. The study shows that by rotating the layers, the VHSs can be controlled, allowing for the tuning of E_F and the VHSs. This provides a powerful tool for manipulating electronic phases in graphene. The experiments reveal that the energy separation between VHSs (ΔE_vhs) depends on the rotation angle. For a rotation angle of 1.79°, ΔE_vhs is approximately 82 meV, while for a smaller angle of 1.16°, it is about 12 meV. The results are consistent with theoretical predictions and show that the VHSs can be controlled by adjusting the rotation angle. The study also highlights the importance of interlayer coupling in forming VHSs, as vanishingly small interlayer coupling prevents their formation. The findings demonstrate that in graphene, unlike in other materials, the position of VHSs can be tuned by controlling the relative angle between layers. As the VHS approaches E_F, a strongly localized charge-density wave (CDW) appears, indicating the potential for inducing and exploring correlated electronic phases in graphene. This work opens new avenues for the engineering of electronic phases in two-dimensional materials.