Interactive web mapping applications enable users to explore geographical data by panning, zooming, and toggling different layers and representations. Most of them also present the data from different points of view, such as top-down 2D abstract maps and 3D first-person realistic immersive views. The transitions between these views are, however, often abrupt, which can leave the user disoriented. We conduct a user study to better understand how different interactive transitions can support users when going from a top-down 2D map to a first-person 3D view. We consider two different strategies to animate the camera, three different strategies to stage the features and camera changes in the transition, and two interaction techniques to set and control the transition. Our results suggest that users are more effective when the transition is animated automatically and when the features are animated before or at the same time as the camera.