How do I check if an object is touching a tag?

I'm creating a third-person ledge climbing game (Like uncharted) but I need to check if my ledge detector is touching a game object with the tag Ledge. At default, a boolean called is climbing is false, but when the ledge detector touches the tag, it should swithc the navigation controls for a new set of climbing controls. Though at the moment, I haven't done the controls, I still need to get my ledge detector to check for tags.

 //Movement
 private Vector3 Velocity;
 [SerializeField] private float Speed;
 [SerializeField] private float JumpForce;
 [SerializeField] private float Gravity;
 public float SmoothTurnTime = 0.1f;
 float TurnSmoothVelocity;

 //Dynamic Climbing
 private bool IsClimbing = false;

 void Start()
 {
 }

 void Update()
 {
     Movement();
     Climbing();
 }

 private void Movement()
 {
     if (IsClimbing == false)
     {
         //Movement Script
         float Horizontal = Input.GetAxisRaw("Horizontal");
         float Vertical = Input.GetAxisRaw("Vertical");

         Vector3 Direction = new Vector3(Horizontal, 0f, Vertical).normalized;

         if (Direction.magnitude >= 0.1f)
         {
             float TargetAngle = Mathf.Atan2(Direction.x, Direction.z) * Mathf.Rad2Deg + Cam.eulerAngles.y;
             float Angle = Mathf.SmoothDampAngle(transform.eulerAngles.y, TargetAngle, ref TurnSmoothVelocity, SmoothTurnTime);
             transform.rotation = Quaternion.Euler(0f, Angle, 0f);

             Vector3 MoveDirection = Quaternion.Euler(0f, TargetAngle, 0f) * Vector3.forward;
             Controller.Move(MoveDirection.normalized * Speed * Time.deltaTime);
         }

         //Sprinting Script
         if (Input.GetKey(KeyCode.LeftShift))
         {
             Speed = 20f;
         }
         else
         {
             Speed = 10f;
         }

         //Gravity and Jumping Script
         if (Controller.isGrounded)
         {
             Velocity.y = -1f;

             if (Input.GetKeyDown(KeyCode.Space))
             {
                 Velocity.y = JumpForce;
             }
         }
         else
         {
             Velocity.y -= Gravity * -2f * Time.deltaTime;
         }

         Controller.Move(Velocity * Time.deltaTime);

     }
    
 }

 private void Climbing()
 {
     if(IsClimbing == false)
     {
           ------------------------------------
         //!~-~!Need Help Here!~-~!\\
           ------------------------------------
     }
 }

If you have an alternative to using an object, please let me know.