In the absence of a holistic view of landscape sustainability, credible data and consistent information are needed to help decision-making and support adaptive landscape management. This course of events highlights a strong need for a tool (system of standards and controls) that can be used by multiple stakeholders (such as NGOs, public authorities, cooperatives, associations, higher education institutes, etc.) to analyze the state and sustainability of landscapes, predict any impact of new projects on the landscape, and develop urban and peri-urban planning policies. However, while consolidated tools of assessment exist, they exhibit complexity in their references. Existing assessment tools also lack specificity and are primarily limited to qualitative approaches. Although large sets of indicators are available and can be adopted, it is crucial to select a new set of non-conventional indicators that provide a holistic view of the various dimensions of the landscape. This review article aims primarily to discuss relevant models and prerequisites in order to later develop landscape indicators to complement—and in many cases—replace existing agro-ecological indicators. Landscape indicators will serve as a baseline for the proposed tool, which will employ a mixed methodology based on both qualitative and quantitative indicators. Additionally, various environmental and landscape indicators are presented and compared to identify the best reference to landscape sustainability. Various fields of application for indicators-based tools and the scales on which they can be applied are also considered. In particular, Lebanese landscapes exhibit variability in characteristics and possess a unique identity with genuine natural and built landscapes. Only recently has there been an increasing interest in sustainability assessment, particularly in relation to Lebanese Landscapes. Unfortunately, there is a likely gap in the studies, planning, and policies related to these landscapes. A tool that can evaluate, protect, conserve, and propose concrete solutions for these landscapes are needed more than ever.